Revert 153060 - Use early expansion for debug_optimize

Revert 153060 - Use early expansion for debug_optimize

https://chromiumcodereview.appspot.com/10828084 tried to do this but did it
only for release_optimize.

BUG=139118, 70107
Review URL: https://chromiumcodereview.appspot.com/10873039

TBR=thakis@chromium.org

We are getting unit_tests and content_unittests failure on Linux Clang (dbg) constently. Try reverting this CL to see if it helps. Sorry!

http://chromegw.corp.google.com/i/chromium/builders/Linux%20Clang%20%28dbg%29/builds/31418/steps/content_unittests/logs/stdio
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=153128